1. Field of the Invention
The present application relates to die placement on a semiconductor wafer, and more particularly to adjusting a die placement to increase yield of the dice formed on the wafer.
2. Related Art
Semiconductor devices are typically manufactured by fabricating the devices on a semiconductor wafer. An individual device is formed as a die on the wafer using known semiconductor fabrication processes. Depending on the size of the die, a single wafer can contain hundreds of dice. The dice are generally arranged in a pattern (i.e., a die placement) on the wafer to maximize the number of dice on the wafer.
During a fabrication process, a processing structure can contact the wafer or emit a substance that contacts the wafer. Dice that are formed in, adjacent, or opposite locations on the wafer that come in contact with the processing structure or the substance emitted by the processing structure are typically bad, meaning that the devices on the dice have unacceptable failure rates or do not function at all. Thus, the overall yield, meaning the total number of good dice formed on the wafer, is reduced.
In one approach to increase yield, the processing structure is moved to adjust the location on the wafer that is contacted by the processing structure or the substance emitted by the processing structure. There are, however, only a limited number of locations where the processing structure can be moved. Additionally, the increase in yield is typically small, particularly relative to the time and cost associated with moving the processing structure.